The effect of decongestion on nasal airway patency and airflow.
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ABSTRACT:
SUBMITTER: Xiao Q
PROVIDER: S-EPMC8277849 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Objectives (1) Analyze the relationship between intranasal airflow distribution and subjective nasal patency in healthy and nasal airway obstruction (NAO) cohorts using computational fluid dynamics (CFD). (2) Determine whether intranasal airflow distribution is an important objective measure of airflow sensation that should be considered in future NAO virtual surgery planning. Study Design Cross-sectional. Setting Academic tertiary medical center and academic dental clinic. Subjects and Methods Three-dimensional models of nasal anatomy were created based on computed tomography scans of 15 patients with NAO and 15 healthy subjects and used to run CFD simulations of nasal airflow and mucosal cooling. Subjective nasal patency was quantified with a visual analog scale (VAS) and the Nasal Obstruction Symptom Evaluation (NOSE). Regional distribution of nasal airflow (inferior, middle, and superior) was quantified in coronal cross sections in the narrowest nasal cavity. The Pearson correlation coefficient was used to quantify the correlation between subjective scores and regional airflows. Results Healthy subjects had significantly higher middle airflow than patients with NAO. Subjective nasal patency had no correlation with inferior and superior airflows but a high correlation with middle airflow (| r| = 0.64 and | r| = 0.76 for VAS and NOSE, respectively). Anterior septal deviations tended to shift airflow inferiorly, reducing middle airflow and reducing mucosal cooling in some patients with NAO. Conclusion Reduced middle airflow correlates with the sensation of nasal obstruction, possibly due to a reduction in mucosal cooling in this region. Further research is needed to elucidate the role of intranasal airflow distribution in the sensation of nasal airflow.
| S-EPMC6062004 | biostudies-literature
Project description:IntroductionThe nasal cycle represents a significant challenge when comparing pre- and post-surgery objective measures of nasal airflow.MethodsComputational fluid dynamics (CFD) simulations of nasal airflow were conducted in 12 nasal airway obstruction patients showing significant nasal cycling between pre- and post-surgery computed tomography scans. To correct for the nasal cycle, mid-cycle models were created virtually. Subjective scores of nasal patency were obtained via the Nasal Obstruction Symptom Evaluation (NOSE) and unilateral visual analog scale (VAS).ResultsThe correlation between objective and subjective measures of nasal patency increased after correcting for the nasal cycle. In contrast to biophysical variables in individual patients, cohort averages were not significantly affected by the nasal cycle correction.ConclusionsThe ability to correct for the confounding effect of the nasal cycle is a key element that future virtual surgery planning software for nasal airway obstruction will need to account for when using anatomic models based on single instantaneous imaging.
| S-EPMC5316304 | biostudies-literature
Project description:PurposeChildren with sensitization to aeroallergens have decreased lung function and nasal patency. Our purpose was to determine the association of sensitization to different aeroallergens with airway function and nasal patency.MethodsFour hundred and eighty-six randomly selected 11 year-old children who lived in Seongnam City were examined. Serum specific immunoglobulin E (IgE) levels against 6 common allergens (Dermatophagoidesfarinae, birch, cat, dog, Japanese hop and Alternaria), impulse oscillometry (IOS) results for the evaluation of airway dysfunction, and acoustic rhinometry for the determination of nasal airway patency were obtained.ResultsIOS indicated that children sensitized to Alternaria (n = 38, 7.8%) and dog dander (n = 69, 14.2%) had decreased lung function, based on resistance at 10 Hz (Rrs10; a? = 0.0072; 95% CI, 0.017, 0.127; P = 0.010) and 1 Hz (Rrs1; a? = 0.038; 95% CI, 0.001, 0.074; P = 0.042). Children sensitized to D. farinae (n = 281, 57.8%) had decreased post-decongestant nasal volume at 0 to 5 cm (a? = -0.605; 95% CI, -1.005, -0.205; P = 0.003), but normal IOS results at all measured frequencies (P > 0.05). Increased serum eosinophil level was associated with Rrs1 (P = 0.007) and Rrs2 (P = 0.018) and post-decongestant nasal volume at 0 to 5 cm (a? = -0.885; 95% CI, -1.331, -0.439; P < 0.001).ConclusionsSensitivity to specific aeroallergens, serum eosinophil count and total IgE level had different associations with upper and lower airway dysfunction in urban children.
| S-EPMC6557775 | biostudies-literature
Project description:Purpose:The effect of red light rhinophototherapy (RLRPT) on nasal patency in patients with a clinical diagnosis of allergic rhinitis was investigated. Materials and Methods:Subjects were randomly divided into 2 groups, with patients in one group given one treatment session of RLRPT, followed by medical treatment. Those in the second group were treated with medical treatment only. The rhinitis symptoms were evaluated both before and 30 minutes after RLRPT and 2 days later. The nasal patency was objectively measured through the use of both active anterior rhinomanometry and acoustic rhinometry before and 30 minutes after RLRPT. Results:All rhinitis symptoms, including nasal congestion, significantly improved 30 minutes after a single RLRPT treatment, but worsened again, particularly for sneezing, 2 days later. Nasal resistance slightly decreased 30 minutes after RLRPT. The first minimal cross-sectional area did not change after RLRPT, but the second minimal cross-sectional area with the volume of the nasal cavity between 2.0 and 5.0 cm from the tip of the nosepiece significantly lessened. Conclusions:This study showed that RLRPL did not objectively improve patient's nasal patency. Registration Number:The trial is registered with NCT03752645.
| S-EPMC6311790 | biostudies-literature
Project description:Decongestion reduces blood flow in the nasal turbinates, enlarging the airway lumen. Although the enlarged airspace reduces the trans-nasal inspiratory pressure drop, symptoms of nasal obstruction may relate to nasal cavity air-conditioning. Thus, it is necessary to quantify the efficiency of nasal cavity conditioning of the inhaled air. This study quantifies both overall and regional nasal air-conditioning in a cohort of 10 healthy subjects using computational fluid dynamics simulations before and after nasal decongestion. The 3D virtual geometry model was segmented from magnetic resonance images (MRI). Each subject was under two MRI acquisitions before and after the decongestion condition. The effects of decongestion on nasal cavity air conditioning efficiency were modelled at two inspiratory flowrates: 15 and 30 L min-1 to represent restful and light exercise conditions. Results show inhaled air was both heated and humidified up to 90% of alveolar conditions at the posterior septum. The air-conditioning efficiency of the nasal cavity remained nearly constant between nostril and posterior septum but dropped significantly after posterior septum. In summary, nasal cavity decongestion not only reduces inhaled air added heat by 23% and added moisture content by 19%, but also reduces the air-conditioning efficiency by 35% on average.
| S-EPMC11375134 | biostudies-literature
Project description:BackgroundGravity, and thus body position, can affect the regional distribution of lung ventilation and blood flow. Therefore, body positioning is a potential tool to improve regional ventilation, thereby possibly enhancing the effect of respiratory physiotherapy interventions. In this proof-of-concept study, functional respiratory imaging (FRI) was used to objectively assess effects of body position on regional airflow distribution in the lungs.MethodsFive healthy volunteers were recruited. The participants were asked during FRI first to lie in supine position, afterwards in standardized right lateral position.ResultsIn right lateral position there was significantly more regional ventilation also described as Imaging Airflow Distribution in the right lung than in the left lung (P < 0.001). Air velocity was significantly higher in the left lung (P < 0.05). In right lateral position there was significantly more airflow distribution in the right lung than in the left lung (P < 0.001). Significant changes were observed in airway geometry resulting in a decrease in imaged airway volume (P = 0.024) and a higher imaged airway resistance (P = 0.029) in the dependent lung. In general, the effect of right lateral position caused a significant increase in regional ventilation (P < 0.001) in the dependent lung when compared with the supine position.ConclusionsChanging body position leads to significant changes in regional lung ventilation, objectively assessed by FRI The volume based on the imaging parameters in the dependent lung is smaller in the lateral position than in the supine position. In right lateral decubitus position, airflow distribution is greater in dependent lung compared to the nondependent lung.Trial registrationThe trial has been submitted to www.Clinicaltrialsgov with identification number NCT01893697 on 07/02/2013.
| S-EPMC9753395 | biostudies-literature
Project description:PurposeVirtual surgery planning based on computational fluid dynamics (CFD) simulations of nasal airflow has the potential to improve surgical outcomes for patients with nasal airway obstruction (NAO). Virtual surgery planning requires normative ranges of airflow variables, but few studies to date have quantified inter-individual variability of nasal airflow among healthy subjects. This study reports CFD simulations of nasal airflow in 47 healthy adults.MethodsAnatomically accurate three-dimensional nasal models were reconstructed from cone beam computed tomography scans and used for steady-state inspiratory airflow simulations with a bilateral flowrate of 250 ml/s. Normal subjective sensation of nasal patency was confirmed using the nasal obstruction symptom evaluation and visual analog scale. Healthy ranges for several CFD variables known to correlate with subjective nasal patency were computed, including unilateral airflow, nasal resistance, airspace minimal cross-sectional area (mCSA), heat flux (HF), and surface area stimulated by mucosal cooling (defined as the area where HF > 50 W/m2). The normative ranges were targeted to contain 95% of the healthy population and computed using a nonparametric method based on order statistics.ResultsA wide range of inter-individual variability in nasal airflow was observed among healthy subjects. Unilateral airflow varied from 60 to 191 ml/s, airflow partitioning ranged from 23.8 to 76.2%, and unilateral mCSA varied from 0.24 to 1.21 cm2. These ranges are in good agreement with rhinomanometry and acoustic rhinometry data from the literature. A key innovation of this study are the normative ranges of flow variables associated with mucosal cooling, which recent research suggests is the primary physiological mechanism of nasal airflow sensation. Unilateral HF ranged from 94 to 281 W/m2, while the surface area stimulated by cooling ranged from 27.4 to 64.3 cm2.ConclusionsThese normative ranges may serve as targets in future virtual surgery planning for patients with NAO.
| S-EPMC6939154 | biostudies-literature
Project description:Background:External nasal dilator strips are used as nonpharmacological therapy to reduce snoring and daytime sleepiness. In a product improvement initiative, a marketed strip (BRNS) and 2 prototype nasal strips were evaluated. Objective:To compare the nasal patency and multiple-use dermal tolerability of the BRNS and prototype nasal strips using both objective and subject-reported outcome measures. Methods:Two studies were conducted separately in healthy volunteers ?18 years of age. A single-day nasal patency randomized crossover study assessed minimal cross-sectional area (MCA; second restriction) and nasal volume (using acoustic rhinometry); nasal inspiratory flow and resistance (using posterior rhinomanometry); and subject-reported evaluations of the BRNS compared with the butterfly strip and teardrop strip prototypes. A single-center, randomized, controlled, parallel-group, evaluator-blinded study assessed dermal tolerability of the BRNS and the butterfly strip over 7 consecutive nights of use, using the Dermal Response Scale (DRS) and subject-reported comfort and ease of removal. Results:In the Patency study (N?=?50), all 3 strips demonstrated significant improvement from baseline in MCA, nasal volume, and nasal flow parameters (resistance and peak flow). The prototype strips demonstrated significantly more improvement in nasal volume than the BRNS, and the butterfly strip showed significantly more improvement in MCA than the BRNS; all strips were similar with respect to nasal flow and subject-reported nasal breathing outcomes. In the Dermal Tolerability study (N?=?82), all subjects scored 0 (no evidence of irritation) on the DRS at all 7 morning assessments; the BRNS was numerically, but not significantly, superior to the butterfly strip on subject-reported outcomes. Conclusion:The Patency study demonstrated significant improvement from baseline in nasal dimensions and flow for all 3 evaluated strips; between-strip differences were confined to nasal dimensions. Both the BRNS and butterfly strip were generally well tolerated, with no evidence of dermal response over 7 consecutive nights of use.ClinicalTrials.gov identifiers: NCT01105949 and NCT01495494.
| S-EPMC6174651 | biostudies-literature
Project description:RationaleComputational fluid dynamics (CFD) simulations of respiratory airflow can quantify clinically useful information that cannot be obtained directly, such as the work of breathing (WOB), resistance to airflow, and pressure loss. However, patient-specific CFD simulations are often based on medical imaging that does not capture airway motion and thus may not represent true physiology, directly affecting those measurements.ObjectivesTo quantify the variation of respiratory airflow metrics obtained from static models of airway anatomy at several respiratory phases, temporally averaged airway anatomies, and dynamic models that incorporate physiological motion.MethodsNeonatal airway images were acquired during free-breathing using 3D high-resolution MRI and reconstructed at several respiratory phases in two healthy subjects and two with airway disease (tracheomalacia). For each subject, five static (end expiration, peak inspiration, end inspiration, peak expiration, averaged) and one dynamic CFD simulations were performed. WOB, airway resistance, and pressure loss across the trachea were obtained for each static simulation and compared with the dynamic simulation results.ResultsLarge differences were found in the airflow variables between the static simulations at various respiratory phases and the dynamic simulation. Depending on the static airway model used, WOB, resistance, and pressure loss varied up to 237%, 200%, and 94% compared to the dynamic simulation respectively.ConclusionsChanges in tracheal size and shape throughout the breathing cycle directly affect respiratory airflow dynamics and breathing effort. Simulations incorporating realistic airway wall dynamics most closely represent airway physiology; if limited to static simulations, the airway geometry must be obtained during the respiratory phase of interest for a given pathology.
| S-EPMC7770091 | biostudies-literature
Project description:Monitoring of nasal airflow and conductance provides crucial insights into the variable nature of the nasal resistance, nasal cycle, and ventilation. We have previously shown that tracking of pressure swings at the entrance of each nasal passage by a dedicated catheter system allows bilateral monitoring of nasal airflow over several hours but requires complex linearization and calibration procedures. Side-selective nasal conductance is derived from linearized and calibrated bilateral nasal pressure swings and corresponding driving pressure, i.e., the transnasal pressure difference derived from an epipharyngeal catheter. Manual analysis of such recordings and computation of instantaneous conductance as the ratio of flow to driving pressure over several hours is extremely tedious, time consuming, and therefore not suitable for routine practice. To address this point, we developed and validated a software for automatic processing of nasal and epipharyngeal pressure recordings as a convenient tool for studying the nasal ventilation. The software applies an eight-parameter logistic model to transform nasal pressure swings into side-selective estimates of airflow that are calibrated and further processed along with epipharyngeal pressure to compute bilateral nasal conductance over consecutive, user-selectable time-segments. Essential processing steps include (1) offset correction, (2) low-pass filtering, (3) cross-correlation, (4) cutting of signals into individual breaths, (5) normalization, (6) ensemble averaging to obtain a mean pressure signal for each nasal side, (7) derivation of airflow, conductance, and further variables. Among four evaluated algorithms for calculation of nasal conductance, the derivative of the airflow-pressure curve according to the mean value theorem agreed closest with the gold standard, i.e., the conductance derived from airflow measured by a pneumotachograph attached to an oral-nasal mask and transnasal pressure. In combination with the nasal catheter system, our novel software represents a valuable tool for use in clinical practice and research to conveniently investigate nasal ventilation and its changes occurring spontaneously or in response to various exposures and therapeutic interventions.
| S-EPMC6330336 | biostudies-literature